In situations where vehicular or pedestrian access is required on certain plots of land, for instance arable land, road or floor mats are often laid to act as a temporary surface to prevent damage to this underlying land.
The floor mats used are generally modular and are usually inserted into position by the use of a crane.
An example floor mat used is the DURA-BASE™ mat by Terrafirma Roadways. A perspective view of this mat is shown in FIG. 1A. The mat is formed of two overlapping rectangular sections. Holes extend around the perimeter of the mat along the non-overlapping portions of the two sections. When two of these mats are placed next to each other, the mats overlap and the holes along the common edge of these two mats line up such that a temporary locking pin can be placed through the holes of both mats to secure the two mats together.
Given their shape and size, handling and placing these mats into position has proved difficult.
One method which has been used has chains which anchor to the four corners of the mat. The chains then connect to a crane arm which lifts the mat. The problem with this lifting method is that the chains are flexible making accurate manoeuvring and placing of the mat difficult.
Alternatively, the mat has been placed onto a forklift. When in the correct position, the forklift operator angles the rails of the forklift downward causing the mat to slide off into position. The method is slow and can cause damage to the mats as they are positioned.
An improved method for lifting these mats involves a grab device from Terrafirma which allows mats, such as DURA-BASE™ mats, to be gripped, lifted, and placed into position. The present invention relates to improvements to this grab device.